Gabrielle Carteris and Mark D. Espinoza play young marrieds Andrea and Jesse Vasquez on "Beverly Hills, 90210." And, in a rather unusual way, their relationship predates Espinoza joining the cast.

Espinoza admits that he never watched "90210" much before he signed on - he was busy acting in regional theater. But his younger sister and her husband, back home in Beaumont, Texas, were huge fans of the show."They even watch all the reruns. They're crazy," Espinoza said with a laugh.

He didn't tell the family that he was up for the part on "90210" until he actually had it.

"I called my sister the day I found out I got the job, and she said, `Oh my gosh! I can't believe this,' " said Espinoza. "She flipped out. For them, it was the biggest thing in the world. They were far more excited than I was."

His sister went on to give him a big surprise about her daughter.

"Then my sister tells me, `You know, we named Gabrielle after Gabrielle Carteris,' " Espinoza said. "She and her husband had been watching the show since it began. He is still a rabid fan of Gabrielle Carteris."

All of which came as quite a surprise to Carteris herself.

"I was embarrassed and I was touched. Very touched," she said. "I couldn't believe it - somebody named their baby after me!"

Espinoza said he's particularly amazed by the coincidence because he never expected to end up as a regular on "Beverly Hills, 90210." When he was first hired, it was for "multiple episodes" - which he thought meant three or four.

"And I didn't think I'd even get the part," he said. "If somebody had said a year ago that I'd be on `90210,' I'd have laughed in their face. It's the last show I ever expected to be on."

The fact is that the "90210" cast had been almost exclusively non-ethnic, and Espinoza was one of the few Hispanics to even appear on the show.

"I have heard from a lot of people that they're excited to see an ethnic character on the show," he said.

What started out to be a short-term gig has turned into a regular co-starring role - in large part because of what was going on in Carteris' life. She'd gotten married, and she and her new husband wanted to have children. "We didn't want to wait to start our life," she said.

The actress admits that she was "afraid" to approach executive producer Aaron Spelling about her desire to have a baby and feared they might write her out of the show entirely.

She needn't have worried.

"Aaron is the best. He was great," Carteris said. "When I came to him and said I wanted to get pregnant, would you write it in, he said, `Absolutely.' "

Soon, not only was Carteris pregnant but so was her character, Andrea. And Andrea ended up marrying the father of her baby, Jesse - played by Espinoza.

And while Espinoza was a latecomer to a series that generated more than its share of stories about strife on the set, he said he's never had any trouble.

"I've never been made to feel less than part of the group," Espinoza said. "I could not have been luckier, because this is my first high-profile job on a series. My job has been made so much easier by the fact that everyone cooperates."

Of course, now that problem child Shannen Doherty is no longer a member of the cast. . . .

"I look forward to the newness," Carteris said firmly and diplomatically, referring to a few other new cast members when asked if she'd miss Doherty. "We're going to have a really great year."

Of course, it may prove to be at least a bit difficult for Carteris this season as she tries to balance her role on the show with her role as a new mother. Carteris and her husband, Charlie, became the proud parents of daughter Kelsey Rose - who was born at almost exactly the same time as her television counterpart.

"The night on `90210' when my character was giving birth, I was giving birth," Carteris said.

She'd been in the hospital all day, having contractions. And when "90210" came on, she and her husband tuned it in on the TV.

"We're watching and Mark (Espinoza), who plays Jesse on TV, is sitting next to Andrea watching the fetal heart monitor. And Charlie, my husband, is sitting next to me watching the fetal heart monitor," Carteris said.

"And then I went into pushing labor, and I don't remember anything else that was on TV. But the baby was born just as `Melrose Place' finished. Isn't that weird?"

("Melrose Place" followed "90210" on the Fox Wednesday night lineup.)

Spelling has had one of the dressing rooms turned into a nursery, and Carteris has hired a nanny. And not only is she getting along with both her husbands - the real one and the TV one - but they also get along with each other.

"He is such a great guy. We play tennis a lot," Espinoza said of his real-life counterpart. "He's been pretty busy lately, though, with the baby."

What Carteris hasn't gotten used to is the difference between her real-life baby and her TV baby, which is actually played by a pair of twins just three days younger than her daughter.

"They're so different looking than my daughter. My daughter's dark and really full, and they're long and fair," she said.

And those fair, blond TV babies are also supposed to be the offspring of tall, dark and handsome Espinoza

"It's TV - everybody will believe it," Carteris said. "If we went and made them frogs, everybody would believe it."